I built a parallel battery harness as see here:
Here is the harness and 2 battery packs in my pede:
The second battery is slung under the chassis to keep the center of gravity low
The straps are bicycle toe-clip straps made of nylon.
I timed the stock pede with a 2400 mah pack and got between 7 and 8 minutes of run-time per pack. With two 2400 packs in parallel I got almost exactly 20 minutes.
These runs are what I would call a typical run by my son. Which is to say, the trigger is full on about 98% of the time. The runs are about 1/2 blacktop and 1/2 grass/woodchips/dirt.
A single 3300 mah pack runs about 18 minutes. I have not had a chance to run two 3300 packs in parallel. I will do that tomorrow.
To keep things interesting, I replaced the wheel bushings with 5-11 stainless bearings tonight.
Does anyone care about this? If not, I will stop posting updates.